Effects of weed "Reestablishment" after hoeing on corn yields

Abstract

Some growers and researchers sustain the idea that regrowth or root setting of some weeds may occur after hoeing, with detrimental effects over corn. The objective of this study was to evaluate the effects of weed removal from the field, removal after each hoeing, and corn intercropped with gliricidia on weed control and corn yield values. The experimental design consisted of blocks with split-plots and six replicates. Cultivars AG 1051 and BM 2022, planted in the plots, were submitted to the following treatments: no hoeing, two hoeings (at 20 and 40 days after planting), and intercropped with gliricidia. The hoed plots were either submitted to weed removal after the first, second, or both hoeings, or remained without weed removal. In the intercropped treatment, gliricidia was sown by broadcasting at corn planting between the corn rows, at a density of 15 seeds m-2. Twenty-five weed species occurred in the experiment; the most frequent was Digitaria sanguinalis (family Poaceae). The weed control methods tested had similar effects on the cultivars, which were not different from one another with respect to the evaluated traits, except for one-hundred-kernel weight, with cultivar AG 1051 being superior. Weed removal did not influence green corn yield or grain yield. However, the number of kernels/ear was higher in plots where weeds were removed in relation to plots without weed removal, suggesting that weed removal might be beneficial to corn. Besides, a higher dry matter weight was obtained for the above-ground part of weeds removed from the field after the first and second hoeings than the weight of weeds removed after the second hoeing only which, in turn, was higher than the weight of weeds removed after the first hoeing only. Green ear yield, grain yield, and dry matter of the above-ground part of the weeds did not show differences in hoed plots and were superior to the non-weeded plots and the intercropped plots, which were not different from each other; therefore, intercropping with gliricidia did not improve corn yield values.

Weed interference periods in sesame crop

“…Weed species observed in the present study are common in the semi-arid region of Brazil (Linhares et al, 2009;Marques et al, 2011;Mesquita et al, 2017). Other species (Ipomoea triloba, Blainvillea lanceolata) were also reported to be present in summer crops of this region (Silva et al, 2009;Silva et al, 2010). The highest weeds dry matter was observed in 2017 for both cultivars (Figure 2).…”

Controle de plantas daninhas na cultura do milho com gliricídia em consorciação

“…Provavelmente, depois das capinas, ocorreu a germinação de sementes de plantas daninhas. Além disso, há indícios de que ocorre o "pegamento" de algumas plantas daninhas após as capinas (Silva et al, 2010a). Resultados semelhantes a esses foram observados por outros autores (Linhares et al, 2009;Silva et al, 2009b), que também estudaram o consórcio milho-gliricídia visando ao controle de plantas daninhas.…”